The Amazon lowlands are located mostly in Northern Brazil, with lesser parts in Peru, Columbia, Venezuela, Ecuador and Bolivia. In its central regions, the river’s gradient rises roughly one centimeter per kilometer, keeping it within a few hundred feet of sea level as far as 2000 miles from the ocean. This low-lying basin is almost completely surrounded by higher ground; to the south the Brazilian Shield, the mighty Andes to the west and the mountainous Guyana Shield to the north. Water flows into the basin from all three highlands directions, and then east, to the Atlantic ocean. The surrounding primary forest canopy returns vast volumes of water to the air through transpiration (release of water vapor through plant pores), helping to retain and circulate water through the basin and driving its internal weather systems.
Amazon Seasons - The majority of the basin sits just below the equator. Coriolis forces (prevailing wind directions caused by the earth’s rotation) are reversed on opposite sides of the equator. This means that weather (and the dry and rainy seasons) tends to rotate counterclockwise through the basin. In the equatorial tropics, temperatures don't vary greatly and seasons are more clearly differentiated by rainfall amounts. Parts of the Amazon may be in the midst of their rainy season, while other areas are in the dry, low-water part of their cycle. The result is a pulsative ecosystem where water levels in lowlands rivers can rise and fall as much as forty feet during the course of a normal year’s rainy/dry cycle. The good news is that the dropping and dry parts of this cycle allow anglers to pursue trophy peacock bass in the Amazon for more than six months of the year.
Every aspect of the trophy peacock bass fishery is governed by this cycle of moisture. At the start of the rainy season, the rivers rise and begin to overflow their banks and the waters spread into low-lying regions of jungle. These cyclically flooded areas, called varzea and igapo in Brazil, gradually form a vast floodplain surrounding the river channel. As the waters rise, the baitfish head off into the jungle to feed on the forage available there and reproduce. The peacocks follow right behind them. Even if anglers didn‘t mind the torrential rains and the discomforts associated with them, finding the fish in the middle of the flooded jungle is next to impossible. Furthermore, if you managed to hook-up, picture the difficulty of threading a fishing line (with a big, extremely uncooperative fish on the end) through a thicket of trunks and leaves and branches. The rainy season is not the time to go peacock bass fishing.
When to Fish - As the rains come to an end in an area and the river that drains it drops, the waters recede from the flooded jungles and once again become confined in the lagoons and river channels. The baitfish, and of course their consumers, the peacock bass, return as well. During the early part of the dry season, the peacocks feed voraciously on the fattened and concentrated baitfish. This is prime time for peacock anglers. After a bout of heavy feeding, they store fat, change their color and pattern and begin to spawn (see articles on color and pattern variation and shape change). The optimal time to fish for peacocks is the period between when water drops below the riverbank level and descends to its lowest level.
Luckily for fishermen, different rivers reach low water levels at different times. Even within a single river, dropping water level may work their way downstream over several weeks. Anglers can fish in the Amazon from August through November in the south and October through March in the northern basin. With adequate mobility, you can access good fishing throughout the period when water levels drop in peacock bass’ habitat.
Black Water — Fed by tributaries draining the austere soils of northwestern Amazonia, the Rio Negro is the center of the Amazon's trophy peacock bass fishery. The region’s waters are extremely acidic and generally low in biomass. The water literally appears black because of staining by dissolved tannins. Tannin is the same pigmented chemical that gives tea its color. In fact, if you look at a cupful of Rio Negro water, it would look very much like a cup of weak tea. When viewed in the gigantic quantities present in this massive river, it simply appears black. Surprisingly, however, visibility is good in these waters. That means that fish are strongly visually stimulated. The look and color of lures becomes important in these conditions.
The tributaries of the Rio Negro (and several blackwater tributaries of the Rio Madeira) provide access to the world's biggest peacock bass. Black water fisheries typically experience their dry season during the Northern hemisphere's fall and winter, September through March. These rivers are strikingly beautiful with their austere surroundings and white sand beaches, set off by richly colored, tannin stained water. The low biomass in these rivers means lower numbers of microscopic animals, lower numbers of baitfish, and consequently lower numbers of peacock bass. But they're big! The world's record 28-pound peacock bass came from blackwater as does the great preponderance of 20-pound plus fish. Anglers fishing in these rivers have a very good chance for a huge trophy fish.
Blackwater peacocks are readily caught on topwater lures. Subsurface lures such as Redfins and Rapalas and of course, the highly effective peacock bass jigs are also very productive. Fish can be found and caught in the lagoons and cuts adjoining these rivers. The lagoons are often quite large with a variety of structure, depths and configurations, offering a wide range of productive possibilities for fishermen.